Combustion system

ABSTRACT

An internal combustion system comprising structure defining a reaction zone for reacting calcium carbide and water to obtain acetylene and calcium hydroxide, structure defining a combustion zone for burning acetylene and producing motive power, including means for transferring acetylene to said combustion zone, and means for passing combustion products of the combustion zone through the calcium hydroxide slurry produced by the reaction zone.

United States Patent Seitz May 23, 1972 54] COMBUSTION SYSTEM 320,394 10 1929 Great Britain ..123 1 A [72] Inventor: Joseph R. M. S8112, Boston, Mass. OTHER PUBLICATIONS [73] Assignee: The whole Earth Corpomfion! Rocklandv Turner, Cyril N., Acetylene Gas How to Make and Use It, Per- Masscival Marshall & Co., London, 1905 pp. 50- 51 [22] Filed: Aug 10, 1970 ldutterfield and Leeds, Acetylene, the principals of its Generation and Use, Grifiin & Co., London 1903, pp. 22 23 and [21] Appl. No.: 62,329 206 207 52 us. c1. ..60/274, 23 2 c, 23/284, f

48/4, 48/38, 60/282, 123 A Att0rney-JohnNoe1W11l1a.ms [51] Int. Cl ..F0ln 3/16, F02b 75/10 58 Field of Search ..123 1 A; 60/30 L; 48/4, 38; [57] ABSTRACT 23/284, 2 C An internal combustion system comprising structure defining a reaction zone for reacting calcium carbide and water to ob- [56] References C'ted tain acetylene and calcium hydroxide, structure defining a v UNITED STATES PATENTS combustion zone for burning acetylene and producing motive power, including means for transferring acetylene to said com- 1,5l4,977 11/1924 McElroy 123/1 A bustion zone, and means for passing combustion products of 2,773,735 12/ 1956 Ruth ...60/3O L the combustion zone through the calcium hydroxide slurry 3,498,767 3/1970 Fostek ..48/38 produced by the reaction zone.

FOREIGN PATENTS OR APPLICATIONS AFTER l BURNER l J EN G I NE ACETYLENE GENERATOR 18 Claims, 7 Drawing Figures SUPPLY Co (0111 (OH)? SCRUBBER EXHAUST PATENTEDMAY 23 I972 SHEET 1 BF 4 fimmmm a m u Av-m mmmmDmOw PATENTEDMAY23|9T2 3,664,134

snwanra @531 FIG. 2

H EAT H2O 00- 0 4 v 1 AIR l REACTION 2 "'2 COMBUSTION zONE ZONE CO,CO2,N2

AFTERBURNER TRACE co SCRUBBER l EX HAUST C0 C0 DRY DRY FERTILIZER PLASTER COMBUSTION SYSTEM This invention relates to engines, particularly to internal combustion engines for vehicles, and to fuels for such engines, including processing of combustion products of these fuels.

A principal object is to provide low-cost, substantially pollution-free internal combustion engine systems utilizing abundant fuel sources, and compatible with present conventional gasoline engine combustion systems.

Another object is to provide a regenerative, and thus highly efficient fuel supply system for combustion engines.

Still another object is to reduce gaseous and even thermal pollution of conventional engines.

In one aspect, the invention features an internal combustion motor comprising structure defining a reaction zone for reacting calcium carbide and water to obtain acetylene and calcium hydroxide, structure defining a combustion zone for burning acetylene and producing motive power, including means for transferring acetylene to said combustion zone, and means for passing combustion products of the combustion zone through the calcium hydroxide slurry produced by the reaction zone. The invention also features a vehicle driven or propelled by this motor through appropriate (conventional) drive means.

In preferred embodiments, the motor also includes an afterburner and means for transferring the combustion products out of the combustion zone either first to the afterburner, and thereafter to calcium hydroxide slurry (for reduction of C in the exhaust), or first to the scrubber and then to the afterburner (particularly for reducing substantial noxious sulfur and nitrogen pollutants).

For carrying out this motor system, there is described a reaction zone including a hydraulic tank having a porous barrier, with a charge of calcium carbide supported on the barrier, a supply of water capable of being maintained beneath the barrier, and control means for exposing the calcium carbide to this water at a controlled rate, for example, by varying the height of the water supply in the tank so as to raise the water level to and above the porous barrier as required for exposing calcium carbide to water to generate acetylene. This tank may contain additionally a supply of a second liquid, immiscible with and lighter than water, and non-reactive with calcium carbide, such as liquified natural gas, which forms with water a two phase liquid system immersing at all times the porous barrier and the calcium carbide charge, the control means varying the height of the interface of these phases for exposing the calcium carbide to water.

One preferred porous barrier is of frusto-conical shape, with the apical end adjacent the interface.

Another preferred porous barrier comprises at least two perforated discs, disposed in face-to-face relation, and mounted for relative rotation with the perforations in the discs mutually arranged to provide composite axial passages through the discs of varying sizes and to be completely closed. A rotary crusher is arranged to rotate closely adjacent the upper disc so as to crush the smallest particles, (which are larger than the diameter of the passage through the discs) between the disc and the crusher to reduce the particles to a size capable of passing through the passages into water beneath. The control means regulates one or both of the speed of rotation of the rotary crusher and the size of the composite passages through the discs.

In a preferred embodiment, the aforesaid motor includes a scrubbing zone wherein the exhaust products are passed through calcium hydroxide, and a water supply, and the reaction zone includes fluid discharge means for discharging calcium hydroxide slurry accumulating at the bottom thereof during generation of acetylene to this scrubbing zone, gas discharge means for transferring generated acetylene gas from the reaction zone, and means for adding replacement water to the reaction zone to replace water removed with the calcium hydroxide slurry.

The invention further features a method for propelling an automobile in which a source of calcium carbonate is chemically reduced to calcium carbide, the calcium carbide is reacted with water in an automobile to produce acetylene and calcium hydroxide, the acetylene is burned in an internal combustion engine of the automobile to propel the automobile, the exhaust products, including C0 are passed through the calcium hydroxide to react with the calcium hydroxide, including reacting carbon dioxide with calcium hydroxide to produce calcium carbonate, and the calcium carbonate thus produced is utilized as a calcium carbonate source for producing more calcium carbide.

The invention further features nonor partially-acetylene burning engines utilizing such systems as described. For example, a zone of the aforesaid motor may include means for compressing and heating said acetylene to provide conditions for trimerizing said acetylene to benzene, and a chamber for explosively igniting and burning the benzene so produced. Or, the acetylene and calcium hydroxide generating system may be used simply as a regenerative pollution control device for removing noxious components from the exhaust products of an internal combustion engine, simply comprising structure defining a reaction zone for reacting calcium carbide and water to produce acetylene and a calcium hydroxide slurry, and means for passing the exhaust products of the engine through this calcium hydroxide slurry to remove noxious components from the exhaust products.

Other objects, features and advantages will be apparent to one skilled in the art from the following description of preferred embodiments of this invention, taken together with the attached drawings thereof, in which:

FIG. 1 is a schematic view of an automobile having an engine system embodying the present invention;

FIG. 2 is a schematic illustration of an acetylene regeneration system;

FIG. 3 is a diagrammatic illustration of an arrangement of apparatus for the system of F IG. 1;

FIG. 4 is a diagrammatic view of an alternative combustion zone useful in the arrangement of FIG. 3;

FIG. 5 is a diagrammatic view, partially broken away, of still another combustion zone arrangement; and,

FIGS. 5a and 5b are sectional views of the arrangement of FIG. 5.

In Fig. 1 there is shown an automotive power system for a wheeled vehicle 10. The vehicle includes a water supply, a calcium carbide supply, an acetylene generator in which the two are mixed for reaction, a reciprocating internal combustion engine powered by the acetylene, drive means, such as a drive shaft arrangement indicated generally at 12 for propelling the vehicle, and a scrubber containing calcium hydroxide through which are bubbled the exhaust gases from the engine. An afterburner is preferably employed downstream of the internal combustion engine, either before or after the scrubber, to complete combustion and oxidation of exhaust products produced in the engine. A heat exchanger such as a radiator 11 is advantageously coupled to the scrubber to prevent excessively high temperatures in the scrubber.

In FIG. 2 there is shown a closed, substantially regenerative system for producing, burning, and scrubbing acetylene. In particular, a carbon-containing substance such as coke, coal or the like is reacted, in conventional manner, with calcium carbonate (or calcium hydroxide, or calcium oxide, according to the carbide process utilized), with the addition of heat (e. g., in an electric furnace) to produce calcium carbide, a solid, granular material which may be ground to fine particles, pelletized, or otherwise manipulated into the most readily useable form.

The calcium carbide is then reacted, under controlled conditions such as will subsequently be illustratively described, in a reaction zone, with water, steam, water vapor, or the like, simply by exposure thereto under atmospheric or desired pressurized conditions, and at ambient temperatures, to produce gaseous acetylene and a solid Ca(OH) which, in water, forms a slurry commonly known as lime hydrate. The generated gaseous acetylene is then passed to a combustion zone where it is admixed with air and ignited. For example, the reaction zone may contain a manifold for providing an ignitable acetylene-air mixture of proper ratio, and a plurality of compression cylinders fed from the manifold, as in the conventional internal combustion engine. The calcium hydroxide slurry is, at the same time, advantageously transported to a scrubbing zone. The exhaust products of the acetylene-air ignition, including C0, C N and lesser quantities of S0 and oxides of nitrogen, such as N 0 are then passed to a regenerative burner where the remaining CO is substantially entirely converted to CO with some concomitant increase in oxides of nitrogen. The sulfur oxides are expected to be produced from sulfur contaminants particularly in the coke but also possibly in the calcium carbonate (e.g., as calcium sulfate or sulfites), The exhaust products of the regenerative burner are then passed to the scrubber where the CO will react with the Ca(OI-I),, to form insoluble calcium carbonate, the sulfur oxides will react to form calcium sulfate or sulfite, and the acidic oxides of nitrogen will form soluble calcium nitrates and nitrites. Only the relatively innocuous N and N 0, as well as perhaps very minor traces of CO will pass from the scrubber into the atmosphere. The scrubber exhaust may also be recycled to further reduce pollutants.

The mixture of calcium carbonates and sulfates (and possibly also sulfites) may be precipitated out from the more soluble calcium nitrites and nitrates, the sulfates subsequently used, e.g., in plaster, and the carbonate recovered from recombination with coke for further production of acetylene. In addition, the dissolved nitrates and nitrites may be recovered from solution and their nitrogen content utilized, e.g., in dry fertilizer compositions. Thus, whereas conventional afterburner systems have the disadvantage that conversion of noxious, CO to CO also causes conversion of the innocuous lower oxides of nitrogen to the pollutant N0 the present afterburner-scrubber system eliminates these afterburner byproducts from the exhaust. Further, since the afterburner-scrubber system eliminates noxious and deadly pollutant sulfur oxides, cheaper, high-sulfur carbon or coke sources can be utilized.

As an alternative to the system shown, gasoline, other petroleum fuels, or even natural gas may be burned in the engine, along with acetylene, with the total exhaust gases passed, as shown, through the afterburner-scrubber system. Thus, previously non-useful high sulfur petroleum or natural gas sources can be utilized directly, without the need to use costly sulfur-refining procedures. To compensate for differences in compression ratio between acetylene and, say, conventional gasoline, required for efficient combustion, the acetylene from the reaction zone may be fed to a separate cylinder for combustion by itself, or, perhaps even more conveniently, trimerized to benzene, which in turn could be admixed with gasoline for combustion with little or no effect on the compression ratio required for gasoline alone. In fact, benzene is presently proposed and used, along with toluene, as an antiknock component in lead-free gasoline. It is conceived that such trimerization could be achieved simply by passing the generated acetylene through or around a hot metal tube-e.g., the exhaust pipe of the automobile (which would thus be advantageously cooled). The acetylene would be passed, e.g., around the hot exhaust manifold of the engine, and thus partially converted to benzene.

In lieu of admixing such benzene with a major gasoline supply, the benzene itself could be used as an adjunct fuel in the engine, at least after start-up. It is conceived that the engine would be started on a rich acetylene-air mixture and, as the engine and hence the exhaust warmed up, the acetylene principally converted to benzene, which would be returned to the engine to replace acetylene as the fuel. Thus, present carburetor designs can be utilized with a primary acetylene fuel source. If desired, certain catalysts, such as organo-vanadium compounds, could be used to enhance the yield of the trimerization reaction.

The acetylene-generating system in the automobile need not be pressured. By providing, additionally, a storage zone located between the acetylene generator and the engine which contains a mixture of sawdust and acetone similar to the material used for low-pressure solution storage of acetylene in cylinders, one can in some instances store a considerable volume of acetylene safely in the car and in this low-pressure tank or slurry array. Thus, there would be possible instantaneous starting simply by providing a few p.s.i. of overpressure, or a small heater, either from a conventional battery energy supply.

Among the advantages of the described system is the elimination of the dependency of internal combustion engines on the worlds rapidly depleting, and often politically uncertain, petroleum supplies and the substitution therefor of superabundant carbon sources such as coal. coke, peat. and the like. In addition, where used in vehicles such as automobiles. the acetylene system described has safety advantages not present in gasoline-fueled engines. Since it is conceived that acetylene will be generated only as needed, and would not be stored, reservoir-fashion, as is gasoline, rupture of the engine in a severe collision would not result in the explosion now ob tained with gasoline. The calcium carbide, itself not explosive, even if immediately doused with water, would at worst result in a steady, frothing fire-but not in explosion.

In addition to the sulfur oxide impurities mentioned, the initial carbide-water reaction, if there are sulfide impurities, could possibly generate hydrogen sulfide. However, this obnoxious gas would be burned to the sulfur oxide in the afterburner, and hence be reclaimed as sulfate or sulfite in the Ca(Ol-I) scrubber. For intermediate transfer of H 5 between zones and the cylinder linings, resistant coatings, such as molybdenum, which forms an H S-resistant self-lubricating surface of M08 may be utilized for sulfur-rich carbides.

In the regenerative burner, no additional fuel need be employed-just exhaust gases from the combustion zone admixed with additional air. It is preferred that the acetylene-air mixture in the combustion zone be acetylene rich, with incompletely burned or oxidized products then completely oxidized in the afterburner. Heat generated by the afterburner may also be utilized to promote the aforesaid trimerization reaction to form benzene.

With regard to impurities in the water, which would preferably be a distilled, non-corrosive water, (although tap water could be used if non-corrosive materials or replaceable water cartridges were employed), mineral substances would not substantially affect or enter into the acetylene-water reaction.

The passing of exhaust gases through the calcium hydroxide slurry further reduces thermal pollution from the regenerative burner. Conventional regenerative burners, utilized in gasoline engines as pollution control devices, can do damage to highway systems, practically melting the asphalt from the freeways with their 600 C exhaust. In the present system, the exhaust gases are bubbled through the calcium hydroxide. Whatever steam may be evolved as the calcium hydroxide becomes quite hot can be cooled by a radiator system or fed back to the reaction zone or Water supply for subsequent reaction with calcium carbide to form acetylene, or even reacted therewith as water vapor. Whatever increase in carbon monoxide might be caused by such a calcium carbide-steam reaction is compensated by the oxidation of that CO to CO in the afterburner.

In FIG. 3 there is shown an arrangement of apparatus for carrying out the carbide-water reaction in the acetylene generator, such as in the vehicle of FIG. 1. In particular, referring to the figure, water storage tank 13 contains a supply of water, sufficient to raise the level of water in reaction tank 14 above porous barrier sheet 16 (e.g., a screen or perforated sheet, made of non-corrodible material), the two tanks being connected by a hydraulic pump 18 and valve 20. Reaction tank 14 is in communication with a supply conduit 22, which delivers, under appropriate pressure, through a valve 23, a slurry of calcium carbide in liquified natural gas (hereinafter, lpg) which may be delivered to the vehicle from pumps such as the gasoline pump of convention gas stations. The lpg will form a top layer 24, by reason of its lighter weight, on water layer 26, with the calcium carbide particles 28 being so sized as not to pass through porous barrier 16. The system is maintained using only a few p.s.i. overpressure on tank 14. Thus a dense calcium carbide slurry will rest on barrier 16. Reaction tank 14 is further connected, through conduit 30, valve 32, and hydraulic pump 34, to scrubbing chamber 36, in which is contained a slurry 37 of calcium hydroxide, the settled solids 38 being periodically drained off from the bottom of reaction tank 14. A heat exchange loop (e. g., a radiator) 39 is provided for recirculating and cooling the slurry 37. Also exiting reaction tank 14 is an acetylene conduit 40, leading to combustion zone 42, which is also supplied, through air conduit 44, valve 45, and filter 46, with atmospheric air. Combustion zone 42 may be, e. g., the manifold and pistons of a reciprocating internal combustion engine, and indicates generally a conventional internal combustion engine, with compression ratios adjusted to be suitable for acetylene ignition and burning. Exhaust gases from zone 42 are passed, through exhaust passage 43, and into afterburner 47, where additional combustion takes place, and therefrom through conduit 48, to scrubber 36. The remaining exhaust products, which do not react with calcium hydroxide, exit by exhaust pipe 50. A drain 52 is located beneath scrubber 36 for periodic removal of solids, such as carbonates, sulfates, sulfltes, in their aqueous nitrate or nitrite slurry. Valves 20 and 32, as well as pumps 18 and 34, may be controlled by, e.g., an accelerator pedal. Steam or water vapor produced in scrubber 36 by passage of hot exhaust gases therethrough may be led, through conduit 53, shown in dotted outline, back, e.g., through condenser 54, to water supply tank 13.

In operation, opening of valve 20, and actuation of pump 18, if desired (although mere hydrostatic pressure could be used, alternatively) will cause the liquified natural gas above the water level to rise as more water is pumped into reaction zone 14 until the water level 60 rises above porous barrier 16, thereby exposing calcium carbide particles to water, producing acetylene and calcium hydroxide. Acetylene gas leaves through conduit 40, and is burned in reaction zone 42, producing exhaust gases which are passed to afterburner 48, where combustion is completed, and thence to scrubber 36. The acetylene will carry a small amount oflpg gas, which may also be burned in reaction zone. If desired, lpg may be used for engine start-up simply by boiling off the required small amount (e.g., by exposure to ambient pressure) through the acetylene conduit 40. Calcium hydroxide, also generated by the calcium carbide-water reaction, will slowly sink to the bottom of tank 14, and be periodically or continually drained to scrubber 36, where it is reacted with afterburner exhaust gases as previously described.

This system avoids premature exposure of the calcium carbide, which is highly sensitive to water, to moisture and hence avoids premature generation of volatile acetylene gas during transport and storage. In the event of accidental exposure of the carbide in its liquified natural gas carrier to moisture, the acetylene generated would merely be absorbed, as a dissolved gas, in the liquified natural gas. It is conceived that a slurry of calcium carbide in liquified natural gas would be delivered from a gas station pump, in a similar manner to present gasoline feed. Used calcium hydroxide (i.e., carbonates, sulfates, etc.) could also be drained, in predetermined increments, at the gas station," into a drainage tank such as now is provided in most such stations for other fluids.

To prevent sloshing, etc., in tank 14 and thus, e.g., premature reaction, suitable partitions (e.g., a honeycomb structure 70), wire grids and the like may be provided, such as shown in dotted outline in FIG. 3 at 70.

In lieu of liquified natural gas, other non-reactive (with the carbide) liquids could be used such as acetone, gasoline, benzene, toluene, or various petroleum fractions.

To prevent violent admixture of water and carbide, with rapid evolution of acetylene (e.g., in the event of a collision), the water level at the bottom of the reactor (thus, the porous barrier level also) may be kept very low-e.g., on the order of one-half inch or so, and the valve 20 connecting water supply tank 12 with reaction zone 14 constructed to prevent flowthrough of water. With pump 18, the liquid level in tank 12 could also be kept sufficiently low that, in the event of valve failure, the hydrostatic equilibrium would result in the water level in zone 14 being beneath the porous barrier 16.

In lieu of the flat porous barrier 16, even more exacting control over acetylene evolution could be achieved by utilizing a tall, thin porous conical container 80, as shown in FIG. 4. Increase in water level 60 to the truncated apical end 81 of container 10 would expose initially only a small surface area of carbide to water, with the surface area increasing as the water is allowed to rise along the porous side of the container. Such containers allow a slow start-up of acetylene generation, and hence avoid pressure surges and other disruptions. Of course, as the carbide exposed to the water is used to form acetylene and hydroxide, new carbide from the slurry will take its place. Hence, for any water level, there will be a substantially constant rate of acetylene formation. As before, calcium hydroxide will be continuously removed and fet to scrubber 36, preferably at a rate approximating its stiochiometric rate of formation in the reaction zone.

Where, for example, the calcium carbide is poorly pulverized or where it contains water-insoluble impurities, it may be necessary to provide means for crushing the impurities or large carbide particles and impelling them through the porous barrier into the water beneath. Thus, insoluble impurities will be removed with calcium hydroxide, rather than forming a mat which could plug porous barrier 16 and thus prematurely cut off acetylene generation.

In FIGS. 5, 5a and 5b there is shown a rotary ricer" 86, consisting of two porous plates 90, 92, each advantageously having holes 93, 94 which can produce when partially offset from one another a resultant passage through the two discs smaller than the smallest carbide particle in the slurry, so that gravity-feed through is not possible. These discs may be rotated relatively to one another by adjusting crank 95 so as to completely seal these holes, or completely or partially align them.

A rotary crusher 96 has upturned leading lips 98, and is closely spaced from plate 90 so as to crush and force particles through plates 90 and 92 as it is rotated by rotating shaft 99, on which it is mounted, by crank 100. Thus, carbide particles can be pushed through the plates into water reaction chamber 102 only when both the holes of plates 90 and 92 are not closed and the crusher 96 is rotated, allowing a dual mode of control over acetylene generation. It is conceived that these carbide particles may be in the form of a dry powder, or in an lpg slurry, the latter still preferred to avoid accidental generation of acetylene due to the water vapor constituting the vapor pressure above the water beneath plates 90, 92 passing up into the carbide and reacting therewith.

Crank 100 may be connected to a clutch arrangement (not shown), being manually operated to start the engine, and thereafter drivingly connected to a transmission system, e.g., driven off of the crank shaft of the vehicle.

The particle size of calcium carbide in the slurry should be chosen small enough so as to provide a sufficiently fluid slurry for rapid filling of the supply tank at the filling station but sufficiently large to limit exposed surface area so as not to produce dangerously high and rapid acetylene evolution upon accidental exposure to water. The slurry-water system may also include additional components to reduce contaminant productions. For example, to avoid possible evolution of noxious and potentially explosive phosgene gas from phosphorous impurities in the carbide, and aqueous ammonia system could be used in lieu of water, or even generated in situ if the carbide were enriched with calcium nitride. The ammonia would, of course, eventually be reduced to harmless lower nitrogen oxides and soluble nitrates in the scrubber.

In general, the efficiency of the scrubber for removing contaminants may be improved if it is located before, rather than after, the afterburner, as shown as an alternative in FIG. 1 both for acetylene-burning engines, and for other hydrocarbon fuel engines, wherein the acetylene system is utilized merely for removal of pollutants. If the scrubber is used before the afterburner, and if at the same time one uses a lean fuel air mixture so as purposely to enrich the exhaust in carbon monoxide, the effect is to make available calcium hydroxide that would otherwise be reacting with carbon dioxide in the exhaust gas. If one enriches the exhaust gas in carbon monoxide-just in carbon monoxide-one makes available additional scrubbing capacity in the form of calcium hydroxide which could be used to neutralize the sulfur content and incidental nitrogen pollution incident to using high sulfur fuels. This system could be used as an adjunct to high sulfur gasoline to eliminate its potential sulfur pollution at the expense of a first stage increase of carbon monoxide, which can subsequently be burned directly to carbon dioxide in the afterburner.

The bulk handling of these acetylene systems is comparable to those of present gasoline engines. It is conceived that calcium carbide could be delivered to gas stations in containerized form, in the form of a perforated metal container with a moisture-proof exterior covering which would be removed and inserted into a housing into the car as the acetylene generator. This container or fuel cell could be on the order of a cubic foot more or less, weighing perhaps 25 to 50 1bs.the equivalent weight to a tank of gasoline. The water tank would be permanently provided in the car, and also replenished as required.

The muddy liquid waste from the scrubber would also be discharged at the gas station, in a drainage pitsomething every gas station in the country has. It could be periodically picked up by the carbide delivery truck, and handled thereafter by being centrifuged or filter pressed to produce a filter cake. The calcium nitrate solution which would be a byproduct, could be boiled down to calcium nitrate which could be used either in the manufacture of nitric acid or other nitrates such as sodium or potassium nitrate, which are of course used generically as fertilizers and in organic chemistry. The same truck which delivers the carbide may return the calcium carbonate to the carbide generation plant where it is simply recombined with more carbon to again produce a source of useful acetylene fuel.

The total slurry discharged would have half the volume of the equivalent gasoline, and water would be added to the water tank to make up for that discharged in the slurry. Thus, it would be a matter of a gas station, which would have water available at any rate, simply receiving dry bulk or containerized calcium carbide in dry powder or slurry form, and storing it in a water tight manner.

Other embodiments will occur to those skilled in the art and are within the following claims.

What is claimed is: v

1. An internal combustion engine apparatus comprising structure defining a reaction zone for reacting calcium carbide and water to obtain acetylene and calcium hydroxide, structure defining a combustion zone for burning acetylene and producing mechanical power, including means for transferring acetylene to said combustion zone, and

means for passing combustion products of said combustion zone through the calcium hydroxide slurry produced by said reaction zone.

2. The apparatus of claim 1 further including an afterburner, and means for transferring said combustion products out of said combustion zone first to said afterburner, and means for transferring afterburner products through said calcium hydroxide slurry.

3. The apparatus of claim 1 wherein said combustion zone includes means for compressing and heating said acetylene to provide conditions for trimerizing said acetylene to benzene, and a chamber for explosively igniting and burning said benzene.

4. The apparatus of claim 1 wherein said reaction zone includes a hydraulic tank having a porous barrier, a charge of calcium carbide supported on said barrier, a supply of water capable of being maintained beneath said barrier, and control means for exposing said calcium carbide to said water at a controlled rate.

5. The apparatus of claim 4 wherein said control means varies the height of said water supply in said tank so as to raise the water level to and above said porous barrier for exposing calcium carbide to water to generate acetylene, and lowering said water level beneath said barrier to cease generation of acetylene.

6. The apparatus of claim 5 wherein said tank also includes a supply of a second liquid, immiscible with and lighter than water, and non-reactive with calcium carbide, said second liquid and water resulting in a two phase liquid system immersing at all times said porous barrier and said calcium carbide charge, said control means varying the height of the interface of said phases for exposing said calcium carbide to water.

7. The apparatus of claim 6 wherein said second liquid is liquified natural gas.

8. The apparatus of claim 6 wherein said porous barrier is of frusto-conical shape, with the apical end adjacent said interface.

9. The apparatus of claim 4 wherein said porous barrier comprises at least two perforated discs, disposed in facetoface relation, and mounted for relative rotation with the perforations in said discs mutually arranged to provide composite axial passages through said discs of varying sizes and to be completely closed, and said control means regulates the size of said passages.

10. The apparatus of claim 9 wherein said discs are arranged to provide passages of diameter less than that of the smallest calcium carbide particles, and including a rotary crusher arranged to rotate closely adjacent the upper disc so as to crush said smallest particles between said disc and said crusher to reduce said particles to a size capable of passing through said passages into water beneath, and said control means regulates the speed of rotation of said rotary crusher.

- 11. The apparatus of claim 1 including a scrubbing zone wherein said exhaust products are passed through calcium hydroxide, and said reaction zone includes fluid discharge means for discharging calcium hydroxide slurry accumulating at the bottom thereof during generation of acetylene to said scrubbing zone, and gas discharge means for transferring generated acetylene gas from said reaction zone.

12. The apparatus of claim 11 including a water reservoir, and said reaction zone includes means for adding replacement water to said zone to replace water removed with said calcium hydroxide slurry.

13. The apparatus of claim 11 including transfer means for transferring steam generated in said scrubbing zone during reaction of hot exhaust products therein back to said reaction zone.

14. A motor vehicle comprising the engine apparatus of claim 1, and drive means utilizing the motive power produced by said engine apparatus to propel said vehicle.

15. A pollution control device for removing noxious components from the exhaust products of an internal combustion engine comprising structure defining a reaction zone for reacting calcium carbide and water to produce acetylene and a calcium hydroxide slurry, and means for passing said exhaust products of said engine through the said calcium hydroxide to remove said noxious components from said exhaust products.

16. The device of claim 15 also including an afterburner, wherein said exhaust products are led first to said afterburner for complete combustion, and thereafter to said scrubber to reduce CO in said exhaust.

17. The device of claim 15 for removing substantial amounts of noxious sulfur and nitrogen components, also including an afterburner, wherein said exhaust products are led first to said scrubber and thereafter to said afterburner for complete combustion of products not removed in said scrubber.

ing CO through said calcium hydroxide to react said exhaust products with said calcium hydroxide, including reacting carbon dioxide with said calcium hydroxide to produce calcium carbonate, and utilizing the produced calcium carbonate as said calcium carbonate source for producing calcium carbide. 

2. The apparatus of claim 1 further including an afterburner, and means for transferring said combustion products out of said combustion zone first to said afterburner, and means for transferring afterburner products through said calcium hydroxide slurry.
 3. The apparatus of claim 1 wherein said combustion zone includes means for compressing and heating said acetylene to provide conditions for trimerizing said acetylene to benzene, and a chamber for explosively igniting and burning said benzene.
 4. The apparatus of claim 1 wherein said reaction zone includes a hydraulic tank having a porous barrier, a charge of calcium carbide supported on said barrier, a supply of water capable of being maintained beneath said barrier, and control means for exposing said calcium carbide to said water at a controlled rate.
 5. The apparatus of claim 4 wherein said control means varies the height of said water supply in said tank so as to raise the water level to and above said porous barrier for exposing calcium carbide to water to generate acetylene, and lowering said water level beneath said barrier to cease generation of acetylene.
 6. The apparatus of claim 5 wherein said tank also includes a supply of a second liquid, immiscible with and lighter than water, and non-reactive with calcium carbide, said second liquid and water resulting in a two phase liquid system immersing at all times said porous barrier and said calcium carbide charge, said control means varying the height of the interface of said phases for exposing said calcium carbide to wateR.
 7. The apparatus of claim 6 wherein said second liquid is liquified natural gas.
 8. The apparatus of claim 6 wherein said porous barrier is of frusto-conical shape, with the apical end adjacent said interface.
 9. The apparatus of claim 4 wherein said porous barrier comprises at least two perforated discs, disposed in face-to-face relation, and mounted for relative rotation with the perforations in said discs mutually arranged to provide composite axial passages through said discs of varying sizes and to be completely closed, and said control means regulates the size of said passages.
 10. The apparatus of claim 9 wherein said discs are arranged to provide passages of diameter less than that of the smallest calcium carbide particles, and including a rotary crusher arranged to rotate closely adjacent the upper disc so as to crush said smallest particles between said disc and said crusher to reduce said particles to a size capable of passing through said passages into water beneath, and said control means regulates the speed of rotation of said rotary crusher.
 11. The apparatus of claim 1 including a scrubbing zone wherein said exhaust products are passed through calcium hydroxide, and said reaction zone includes fluid discharge means for discharging calcium hydroxide slurry accumulating at the bottom thereof during generation of acetylene to said scrubbing zone, and gas discharge means for transferring generated acetylene gas from said reaction zone.
 12. The apparatus of claim 11 including a water reservoir, and said reaction zone includes means for adding replacement water to said zone to replace water removed with said calcium hydroxide slurry.
 13. The apparatus of claim 11 including transfer means for transferring steam generated in said scrubbing zone during reaction of hot exhaust products therein back to said reaction zone.
 14. A motor vehicle comprising the engine apparatus of claim 1, and drive means utilizing the motive power produced by said engine apparatus to propel said vehicle.
 15. A pollution control device for removing noxious components from the exhaust products of an internal combustion engine comprising structure defining a reaction zone for reacting calcium carbide and water to produce acetylene and a calcium hydroxide slurry, and means for passing said exhaust products of said engine through the said calcium hydroxide to remove said noxious components from said exhaust products.
 16. The device of claim 15 also including an afterburner, wherein said exhaust products are led first to said afterburner for complete combustion, and thereafter to said scrubber to reduce CO2 in said exhaust.
 17. The device of claim 15 for removing substantial amounts of noxious sulfur and nitrogen components, also including an afterburner, wherein said exhaust products are led first to said scrubber and thereafter to said afterburner for complete combustion of products not removed in said scrubber.
 18. A method for propelling an automobile comprising providing a source of calcium carbonate, chemically reducing said calcium carbonate to calcium carbide, reacting calcium carbide with water in an automobile to produce acetylene and calcium hydroxide, burning said acetylene in an internal combustion engine of said automobile to propel said automobile, passing the exhaust products of acetylene combustion, including CO2, through said calcium hydroxide to react said exhaust products with said calcium hydroxide, including reacting carbon dioxide with said calcium hydroxide to produce calcium carbonate, and utilizing the produced calcium carbonate as said calcium carbonate source for producing calcium carbide. 